Helianthemum ledifolium
Spotted Rock Rose
This source reports two treatments. Both are shown.
Protocol 1
DerivedN. C. Deno, 1993Difficulty Low
Start around March 29, 2027 for a May 3 last frost.
Warm moist stratification
Temperature: 70°F 21°C
30% germinated here, in 3-7 days.
Cold moist stratification
Temperature: 40°F 4°C
Warm moist stratification
Temperature: 70°F 21°C
No stated waiting before sowing. Then 7 days to germinate.
30% germination in 3–7 days.
This source doesn't state how long.
Protocol 2
DerivedN. C. Deno, 1993Difficulty Moderate
Start around January 18, 2027 for a May 3 last frost.
Cold moist stratification
Temperature: 40°F 4°C
16% germinated at 40 itself, in 4-11 weeks.
Warm moist stratification
Temperature: 70°F 21°C
A further 5% after the move.
No stated waiting before sowing. Then 77 days to germinate.
16% germination in 28–77 days.
Half the germination of sowing straight at 70, and months slower.
This source doesn't state how long.